find non-ASCII characters in a string

nonascii.sh

#!/bin/sh

usage(){
    echo "
find non-ASCII characters in a string
Usage: $0 STRING
"
exit 0
}

if [ "$#" -ne 1 ]; then
    usage
fi

array=$(echo "$1" | grep -o .)

for char in $array; do
    if [ $(printf '%d' "'$char") -gt 127 ]; then
        echo $char
    fi
done